Saturated terpene resins



Patented Oct. 2,1945

OFFICE SATURATED TnRPENE RESINS Alfred L. Rummelsburg, Wilmington, De1., assignor to Hercules Powder Company, Wilmington, Dcl., a corporation of Delaware No Drawing.

15 Claims.

This invention relates to new resinous compositlons of matter and to processes for their production. More particularly, it relates to saturated resins prepared bymeans or the hydrogenation of a liquid unsaturated bicyclic terpene hydrocarbon compound and the subsequent polymerization of the hydrogenated terpene compound in the presence of a suitable catalyst.

Saturated resins formed in accordance with the methods known in the prior art are prepared by first forming an unsaturated resin which is then saturated by means or a hydrogenation operation using extreme conditions oi temperature and pressure. The resulting resins formed under these conditions are undesirable in many respects and their commercial usefulness is limited. Saturated terpene resins produced in accordance with the present invention overcome the undesirable characteristics tound in the prior art saturated resin.

Now. in accordance with this invention, saturated terpene resins may be prepared from unsaturated bicyclic terpenes as, for example, alpha and beta pinene, or from saturated bioyclic terpenes as, forexample, pinane. Where an unsaturated bicyclic terpene is used as the starting raw material as, for example, alpha or beta pinene, the material is first subjected to a nuclear hydrogenation operation to form a saturated bipound is then treated with a suitable polymerization catalyst. Where a saturated bicyclic ter- Applicatlon January 15, 1942 Serial No. 426,857 v an initial pressure of 1200 lbs. per sq. inch and at an initial temperature oi 115 C. for a period of 10 minutes. During the hydrogenation operation, the mixture was agitated to insure intimate 5 contact 01' the hydrogen throughout the mixture. I At the completion of the hydrogenation, the pressure in the apparatus had dropped to 5 0 lbs. per sq. inch and the temperature had risen to 149 C. The reduction of the pinene mixture was strongly 10 exothermic. The resulting pinane was separated Refractive index 1.46llat 21 C. Specific gravity 0.8589 at /200.

Boiling point 168.2C. Specific rotation. '+13.5C. Iodine number..- 5.0 Thiocyanate numberue Nil 20 Unpohnnerized residue Saturation by hydrogen absorption..- 101% cyclic terpene hydrocarbon, which saturated compene as. for example, pinane is used as the starting product, the above procedure is followed except that the hydrogenation operation is omitted.

More particularly, a saturated terpene resin may be produced from alpha pinene by subject-.- ing the liquid unsaturated terpene hydrocarbon to a hydrogenation operation which includes treatment with hydrogen at apressure of 500 to 1800 lbs. per square inch at a temperature or, about 100 C. in the presence of a suitable catalyst as, for example, reduced nickel on keiselguhr. The resulting saturated terpene hydrocarbon, pinane, is then treated with a suitable polymerization catalyst as. for example, an anhydrous halide of an amphoteric metal, to form a saturated terpene resin. x

The method of preparing a saturated bicyclic terpene hydrocarbon and a saturated terpene resin in accordance with this invention is illustrated in the following specific exampleaall parts and percentages being by weight muess otherwise specified.

Hydrogenation of alpha-plume to pinane 158.2 g. or alpha-pinene were hydrogenated in the presence of 8 g. of a, 16% reduced nickel on Filter-Cel (diatomaceous earth) catalyst under from the catalyst by filtration. The physical characteristics 01' the pinane were as follows:

, Exam, LI 2 Polymerization of plnane using a metal halide Boiling point e 168.0 C.-l69.9 C. Refractive index 1.4614 at 20 C. Thiocyanate values"--. Nil

8.? g. 01' this pinane was dissolved in 300 g. of

ethylene dichloride to which solution were added 10 g. of anhydrous aluminum chloride at a temperature of 25 to 30" c.. agitating the mixture hours at 25 to 30 0.

00 cobalt driers.

constantly. A strongly exothermic reaction occurred and the temperature increased to about 65 C, within 0.5 hour, after which the reaction mixture was cooled and. allowed to stand for 18 The ethylene dichloride solvent and excess pinane were removed by steam distillation from boiling water. 7 The saturated terpene polymeric residue was then extracted with ether, and water washed. Evaporation oi the ether left a residue of g. of viscoueoil having the following characteristics:

Thiocyanate number 32 Iodine number a "17 Color I Molar weight -(Rast) ..e 200 Theseturated terpene polymer was only slight 1y soluble in acetone and alcohol and was soluble in thepresence or lead and Exam: 3

Polymerization of pinane using fullers earth In this example, 50 g. oi. pinane and 25 g. of iuller's earth which had been calcined ior hour at approximately 400 C. were agitated in a stainless steel bomb for 9 hours at a temperature of 225 to 250C. The system was cooled and the contents removed and the saturated terpene resin separated from the catalyst by means of filtration. The filtrate was evaporated by vacuo distillation employing a final-bath temperature of 180 C. and pressure of 15 mm. mercury toremove the unreacted pinane. The realdue consisting of 30 g. of viscous oil'had a color characteristic of F+ (Lovibond). The solubility characteristic and drying properties 01 this resin are similar to the resin produced in Example 2.

Exams-r 4 Polmerization of pinane using boron trifluoride In this example, 50 g. of pinane were dissolved in 50 g. of benzene and treated with gaseous boron trifluoride for a period of approximately 1 hour at a temperature or 10 to 15 C. with constant agitation. During this treating operation, approximately 2 g. 01' gaseous boron trifluoride were absorbed. The reaction mixture was allowed to stand at C. to 3 C. for a period of 70 hours. The reaction mixture wa then water washed in order to remove the catalyst and the washed saturated terpene resin was subjected to -vacuo distillation in the manner described with reference to Example 2. A residue of approximately 8 g. of viscous oil was obtained having a color characteristic of F and solubility characteristics anddrying properties similar to the resin produced in Example 2.

, Exmaa Polmerization of pinane using sulfuric acid In this example, 50 g. of pinane were heated with 4 8. of 85% sulfuric acid at 160 C. for a period of 1 hours during constant agitation of the mixture. The resulting polymerized mixture.

. 2. A yield of 3 g. of black colored residue was obtained having solubility characteristics and drying properties similar'to the resin described with reference to Example 2.

Exams: 6

Polymerization of thujane using aluminum chloride In this example, 87 g. of thujane were dissolved in 300 g. of ethylene dichloride. To this mixture were added g'. of anhydrous aluminum chloride at to C. with constant agitation. The reaction mixture was allowed to stand for 18 hours at C.

The ethylene dichloride solvent and excess thuiane were removed by steam distillation from boiling water, as described in Example 2. The polymeric residue was then extracted with ether and water washed. Evaporation of the ether left a residue of viscous oil having solubility characteristics and drying properties similar to the resin described in accordance with Example 2 asaaoes v mu: Polymerization of carane using aluminum chloride In this example, 87 g. of carane were dissolved in 300 g. of ethylene dichloride. 10 8. of anhyand water washed. Evaporation oi the ether leit a residue oi! viscous oil having solubility characteristlcs and drying properties similar to the resin described with reference to Example 2.

The liquid bicyclic terpene hydrocarbons found most suitable for the purposes of this invention are those hyrocarbons containing a cyclopropane or a cyclobutane ring as, for example. alpha or beta pinene, alpha and beta thuiene and alpha and beta carene.

It has been discovered that alpha pinene is easily hydrogenated at relatively low temperatures and low pressures in the presence of a suitable catalyst as, for example, nickel, which may be suspended on any suitable structure as, for example, Filter-Gel or kieselzuhr to form plnane. For example, alpha pinene is completely hydrogenated a: pinane by treatment in any suitable apparatus with hydrogen at a pressure or about 500 or about 1800 lbs. per square inch and at a temperature 0! about 100 C. in the presence 0! about 3.5% by weight of reduced nickel on kieselsuhr. as a catalyst. Raney nickel catalyst may also be employed.

Other unsaturated bicyclic terpene hydrocar bons that may be treated are thuJene and carene, each oi which may be converted to the saturated hydrocarbon thuiane and carane respectively by reduction with hydrogen in the presence of platinum black, or other well known hydrogenation catalysts.

After the preparation of the saturated bicyclic terpene hydrocarbon, the hydrocarbon is treated with a suitable catalyst with or without the presence or an inert solvent, for a suitable period of time for the preparation or saturated terpene resins in accordance with this invention. The catalysts operable in the processes are the anhydrous metallic halides as, for example, aluminum chloride, stannic chloride, zinc chloride, etc. 0! the metallic halides, anhydrous aluminum chloride is preierred Boron triiluoride and its organic complexes may also be used as catalytic agents. Acid catalysts as, for example, suliuric acid, hydrogen fluoride, phosphoric acid, tetraphosphoric acid and HZBFi may be employed, but they are less preferable than the metallic halides. particularly aluminum chloride. Activated clays such as iullers earth, and synthetic activated clays such as magnesium silicates, etc. may also be employed as catalysts, but they are less preferable than is aluminum chloride. It is iound that calcinatlon at 200 C. to 500' C. improves the activity oi the clays as catalysts.

Inert solvents that may be used as a diluent tor the terpene hydrocarbons to be treated are the liquid aliphaticand aromatic hydrocarbons as, for example, benzene, toluene, hexane, octane, etc. Halogenated hydrocarbons may also be used as a solvent for the terpene hydrocarbons, especially carbon tetrachloride, chloroform, ethylene dichloride, halogenated butanes, acetylene a,sse,oes

ated solvent, and particularly ethylene dichloride is particularly useful as a terpene hydrocarbon solvent when the metal halide catalysts, aluminum chloride, and stannic chloride are used.

The ratio of the metal halide and acid catalyst to the saturated bicyclic terpene hydrocarbon may vary from about 0.01 to 1.0 and the ratio is preferably from about 0.02 to about 0.2. In the case of activated clay catalyst, the preferred ratio is from about 0.5 to 1.0.

The reaction temperature during the polymerization operation in the presence of metal halide or acid catalysts may vary from about C. to about 300 C. and is preferably maintained at about 20 C. to 150 C. Where an activated clay catalyst is used, the preferred temperature is from about 150 C. to about 250 C.- A closed system will be necessary when operating at a polymerization temperature which is above the boiling point of the terpene hydrocarbon being polymerized.

The reaction time may vary from about 1 to about 72 hours depending upon the reacting materials used and the conditions under which the reaction is carried out. It is preferable to ad- 7 Just the reaction conditions so that the polymerization operation is carried out in from about 2 to about 12 hours.

After the polymerization operation is complete, the catalyst may be removed in any suitable manner as by washing. The metal halide or acid catalyst may be removed from the reaction mixture by means of a water wash. Particularly in the case of the metal halide catalyst as, for example, aluminum chloride and stannic chloride, a complex is formed between the polymer and the catalyst which ,may be broken down by means of a cold aqueous inorganic acid wash followed by a water wash. Preferably, a hot aqueous solution of 5 to 50% sulfuric acid may be employed to facilitate the break-down of the catalyst-polymer complexes. After completion of the acid and water washing operations. it isdesirable to treat the reaction mixture with a suitable adsorbent in order to remove traces of dispersed metal halide catalyst and metal halide-polymer complexes where not removed during the washing operation.

Adsorbents found operable are diatomaceous earth, activated carbon, activated clays and the like.

When the polymerization catalyst used is an activated clay removal thereof from the reaction mixture may be made by means of any suitable filtration operation. It is to be" noted that in the case of an activated clay catalyst, the water washing step is eliminated and complete removal is made by the nitration operation alone.

Solvent and unreacted terpene hydrocarbons may be removed from the mixture by means of distillation employing steam orvacuo or a combination of both.

Generally, the saturated polymers obtained by means of the polymerization of a saturated terpene hydrocarbon consist of a viscous oil containing a mixture consisting predominantly of the dimer, together with lesser amounts of trimer, tetramer and higher polymers of the hydrocarbon being polymerized. Both the viscosity and melting point of the product may be substantially increased by removing the lower polymers as, for example, the dimer and eventhe trimer by means of vacuo distillation.

The use of an inert atmosphere as, for ex- 3 ample, nitrogen or carbon dioxide to blanket the reaction mixture during the polymerization op-' eration aids in the preparation of pale colored products. The saturated products may be further refined by the use of selective solvents as, for

Suitable adsorbexample, furfural, phenol, etc. cuts as, forexample, fullers earth, activated carbon, synthetic magnesium, chromium, and calcium silicates, etc. may also be used to remove the color producing bodies from the product.

The saturated polymers produced in accordance with, the presentinvention are useful as adhesives,

with a metal halide catalyst capable of polymerizing said terpene at a temperature between about 20 C. and about C. until polymerization is substantially complete.

3. The process of preparing a polymer which comprises treating a saturated blcyclic terpene with an acid catalyst capable of polymerizing said terpene at a temperature between about 20 C. and about 150 C. until polymerization is substantially complete.

4. The process of preparing a polymer which comprises treating a saturated bicyclic terpene with an activated clay catalyst capable of polymerizing said terpene at a temperature between about 150 C. and about 250 C. until polymerization is substantially complete.

5. The process of preparing a polymer which comprises treating a saturated bicyclic terpene hydrocarbon having a cyclopropane ring with a catalyst capable of polymerizing said terpene at a temperature between about 0 and about 800 C. until polymerization is substantially complete.

6. The process of preparing a polymer which comprises treating a saturated bicyclic terpene hydrocarbon having a cyclobutane ring'with a catalyst capable of polymerizing said terpene at a temperature between about 0 C. and about 300 C. until polymerization is substantially complete 'l. The process of preparing a polymer which comprises treating thuJane with a catalyst capable of polymerizing said terpene at a temperature between about 0 C. and about 300 C. until polymerization is substantially complete.

8. The process of preparing a polymer which comprises treating carane with a catalyst capable comprises treating thuiane .with fuller's' earth in the presence of an inert solvent at a temperature between about 150C. and about 250 C. until polymerization is substantially complete.

11. The process of preparing a polymer which comprises treating carane with sulfuric acid in the presence of an inert solvent at a temperature process of preparing a polymer which 'V comprises treating pinane between about 20' C. and about 150' C. until polymerization is substantially complete.

12. The process or preparinz a polymer which with a metal halide catalyst capable of polymerizing said. terpene at a inperature oi between about 0' 0. and about 30 C. until polymerization is substantially cometc. I 13. The procees or preparing a polymer which comprises treatinz pinane' with anhydrous aluum chloride in the presence or an inert soiventat a temperatiu'e between about 20' C. and 

